Taking the Bohr radius as a0=53pm, the radius of Li++ ion in its ground state, on the basis of Bohr's model, will be about:
1. 53 pm
2. 27 pm
3. 18 pm
4. 13 pm
(c)Hint: The atomic radius depends on the atomic no.
Step 1: Compare the atomic no. of Lithium and Li++.
The atomic number of lithium is 3, therefore, the radius of Li++ ion in its ground state, on the basis of Bohr's model, will be about 13 times to that of Bohr radius.
Step 2: Find the atomic radius of Li++.
Therefore, the radius of lithium-ion is near 553≈18pm.